It is proposed to develop a target for production of iodine-124 for commercial distribution and to develop a radiolabeling business for I-124 radiotracers. I-124 is an increasingly useful nuclide for positron emission tomography, especially to label molecules, such as antibodies or other macromolecules including nanoparticles, that require long-duration experiments compared to more common PET protocols It has limited commercial availability. There is a prohibitively high price from a single monopolistic foreign-owned supplier. An additional competitive supply of the nuclide in the United States is a desirable outcome of this work, but the goal of the work reaches beyond that. Current target designs are low-yield and marginal for commercial production. Improvement in the target performance will provide a more economical production environment and lower price. By making a commercially feasible target available to large-scale producers we will encourage increased production and a larger number of production sites. This will allow more economical production and distribution patterns to allow I-124 to be commonly used Possibly the most significant goal of this work is to expand the current business model for I-124 beyond simple production and distribution. We are unique among potential producers in having a fully capable radiochemistry laboratory and capable and experienced radiochemists to perform radiolabeling. The radionuclide will be used to produce a variety of useful radiopharmaceuticals for delivery to customers who lack radiosynthesis facilities. We will offer custom labeling services to prepare proprietary labeled antibodies and other materials produced by or owned by customers. Custom labeled product will be delivered for use in PET scanning experiments. This is expected to appeal to both academic and industrial customers, including large pharmaceutical companies. PUBLIC HEALTH RELEVANCE: Iodine-124 has considerable potential for widespread clinical use as well as the more immediate demands for research use. The economic and scientific advantages that it offers apply to research and development of clinically relevant therapies. These are primarily for cancer treatment but also for all other areas of medical research. This work will have a direct impact on the speed and cost of development of advances in medical practice and of new drugs. All of this requires availability of the radionuclide and of radiotracers that incorporate it, which are the subject of this proposal. The proposal will develop a new commercial production target for I-124 and a business based on production of materials labeled with I-124. The immediate impact will be a reduction in cost of a variety of types of medical research, and inexpensive and higher-throughput screening of antibody candidates for imaging and therapy. [unreadable] [unreadable] [unreadable]